In the ink-jet recording head, a constitution is adopted, in which a nozzle plate as a head member has a large number of micro ejection ports to eject ink, the micro ejection ports being formed to be separated at a micro interval from one to another. FIG. 13 is a sectional view of the nozzle plate of the ink-jet recording head. This nozzle plate 200 is provided with ejection ports 202 to eject ink 201. As shown in FIG. 13(a), the ink 201 is ejected from ejection surfaces 203 of the ejection ports 202 toward a printing surface.
However, as shown in FIG. 13(b), attached ink 204 sometimes remains on tip surfaces (ejection surfaces) 203 of the nozzle plate 200. In such a case, when ink 205 ejected the next time contacts the remaining attached ink 204 as shown in FIG. 13(b), an ejection trajectory of the ink 205 is bent, being affected by surface tension, viscosity or the like of the attached ink 204. As described above, since printing cannot be performed to a specified spot when the attached ink 204 remains on the ejection surfaces 203, pretreatment is required so that the attached ink 204 will not remain on the ejection surfaces 203.
Heretofore, the ejection surfaces 203 have been subjected, for example, to eutectoid plating with fluorocarbon resin and nickel to make the ejection surfaces 203 ink-repellent, so that the ejected ink 201 would not remain on the ejection surfaces 203.
However, as shown in FIG. 14, when ink-repellent films 206 are formed, fluorocarbon resin 207 are attached onto the ejection ports 202 in some cases. Since flows of the ink into the ejection ports 202 are hindered by the fluorocarbon resin 207 when such fluorocarbon resin 207 are attached, removal of the fluorocarbon resin 207 from the ejection ports 202 has been required.
Heretofore, the fluorocarbon resin 207 have been made not to remain in the ejection ports 202 by methods shown in FIG. 15 and FIG. 16. The method shown in FIG. 15 is a method for preventing the attachment of the fluorocarbon resin 207, in which a plug member 208 such as plastic fills the ejection ports 202 before the ink-repellent films 206 are formed. The eutectoid plating is performed after filling with the plug member 208 as described above, thus the fluorocarbon resin 207 can be prevented from being attached onto the ejection ports 202 when the ink-repellent films 206 are formed. Moreover, the method shown in FIG. 16 is a method for removing the fluorocarbon resin 207 attached onto the ejection ports 202, in which the fluorocarbon resin 207 are removed by ultrasound cleaning. Specifically, the nozzle plate 200 is immersed, for example, in an organic solvent 209, and the organic solvent 209 is flown into the ejection ports 202. Then, ultrasound 211 is generated in the organic solvent 209 by an ultrasound generating source 210 disposed under the organic solvent 209. By this ultrasound 211, the fluorocarbon resin 207 attached onto the ejection ports 202 have been removed.
However, there have been problems as below in the conventional methods.
The conventional ink-repelling method by the eutectoid plating with the fluorocarbon resin and the nickel has required much time and labor as cleaning of the nozzle plate before and after the plating was required, which has been a cause of lowering productivity and increasing the labor. Moreover, in the case where the ink ejection ports have a complicated shape, spots not being subjected to the plating may exist on the ejection surfaces. When such spots not being subjected to the plating exist on the ejection surfaces 203, the attached ink remains on the spots, and the ink changes its ejection trajectory, which has been a problem. And, since the eutectoid plating includes not only the fluorocarbon resin but also the nickel, ink repellency is deteriorated by that amount. Moreover, since it takes time to form the eutectoid plating, there has been a problem in terms of working efficiency. Still further, when the ink-repelling method using the eutectoid plating is performed, there has been a problem since a cost thereof is high.
Moreover, in the above-described method for preventing the attachment of the fluorocarbon resin in the ejection ports, since the ejection ports have a port diameter of about several ten μm, which is micro, it takes time and labor to fill the ejection ports with the plug member and to remove the same from the ejection ports. Furthermore, there is a possibility that the plug member is attached onto the ejection ports.
Furthermore, also in the method for removing the fluorocarbon resin by the ultrasound cleaning, since the ejection ports are micro, cleaning using the ultrasound has been time-consuming. Moreover, when the organic solvent flown into the ejection ports contacts the formed ink-repellent films because of the solvent's surface tension, even the ink-repellent films are removed, which has been a problem.
The present invention was made in order to solve the foregoing problems, and has an object to form an ink-repellent film high in ink repellency on a head member by use of plasma polymerization.
Moreover, the present invention has an object to provide a head member having high ink repellency.
Furthermore, the present invention has an object to form an ink-repellent film on a head member at a low cost.
Still further, the present invention has an object to form an ink-repellent film high in durability on a head member.
Yet further, the present invention has an object to remove fluorocarbon resin in ejection ports as micropores without affecting peripheries thereof.